Field
This application is directed to a unique grease gun construction having multiple advantages over such guns which are available in the market place in regard to the ease of manufacture, utility, cost, and operation, and wherein the gun components can be manufactured practically entirely of molded plastic such as polyolefin, butyrate, polyurethane, polyesters, polyamides, or the like, wherein the grease cartridge requires no grease pressurizing spring or outer supporting barrel which is typically of metal, and wherein the present cartridge, preferably, is transparent for allowing the operator to clearly view the grease material within the cartridge whereby the type, composition, brand or the like and the amount of grease dispensed to, e.g., the ZERK fitting, and to view the amount of grease remaining in the cartridge, or to view a contaminant, e.g., water or solids in the grease or any separation of grease components, e.g., into layers.
Prior Art
Heretofore, grease guns have been constructed mainly of expensive, relatively heavy metal parts such as the grease cartridge containing heavy metal barrels and cartridge containing a steel grease pressurizing spring and a spring compression rod (cocking plunger), and a metal grease pumping and ejection head, wherein the cartridge loading operation for such structures, particularly where the pressurizing spring cocking plunger must be retracted and held in place while the cartridge is positioned in the barrel, can be a difficult operation for many operators. Also, such structures do not allow the operator to view the contents of the cartridge or the legends on the cartridge wall surface which denote, e.g., the type of grease, the source information, the amount of grease in the cartridge, and the condition of the grease, e.g., whether separation of the grease has occurred, in the cartridge. Further the present invention, in a preferred embodiment is constructed to so as prevent removal of an empty cartridge and its replacement with a cartridge having the wrong and deleterious type of grease for some highly sensitive application
Typical of such prior art grease gun structures are shown in U.S. Pat. Nos. 1,697,217; 1,714,214; 4,601,412; 3,187,959; 1,633,356; 1,812,643; 3,393,840; 3,341,084; 2,284,533, the disclosures of which are hereby incorporated herein by reference in their entireties.